The processing of gustatory information by neurons in the hamster brainstem will be studied using electrophysiological techniques. Neurons in the nucleus tractus solitarius and the parabrachial region of the pons will be examined for their responsiveness to a variety of stimuli and the size and location of their receptive fields noted. Particular attention will be given to the possible convergence of taste inputs from different areas of the mouth onto single neurons in the brainstem, and also to the patterns of convergence from separate single papillae on the anterior portion of the tongue. Factor analytic techniques will be applied to data from medullary and pontine neurons in an effort to determine whether neuron types exist at these levels, even in the face of an increased breadth of responsiveness of individual neurons.